This video does a very good job explaining how plaques and tangles form in the brain. The animations in the video illustrate the protein and enzyme processes that create plaques and tangles. This is a helpful video for people that want to understand the role plaques and tangles play in the development of Alzheimer’s disease.
In summary, plaques and tangles are misfolded proteins that cause damage to the brain. Plaques block signaling and communication between cells. They also appear to cause immune reactions that destroy disabled nerve cells. Tangles, the other misfolded protein, initially cause problems with short term memory. Over time, tangles cause problems in other areas of the brain. Eventually, plaques and tangles cause damage to the control centers of the brain that govern heart rate and breathing, leading to death.